• Journal of Pharmaceutical Investigation
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• v.28 no.2
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• pp.73-80
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• 1998

In order to elucidate the effect of N-demethylation on the in vivo metabolite kinetics, especially hepatic first-pass effect of trimebutine(TMB), the N-demethylation of TMB to N-monodesmethyl trimebutine(N-TMB) was studied in rats. TMB(10 mg/kg) and N-TMB(10 mg/kg) were injected into the femoral and the portal vein, respectively. And the pharmacokinetic parameters were obtained from the plasma concentration-time profiles of TMB and N-TMB determined by the simultaneous analysis using high-performance liquid chromatography. It was supposed that these drugs were almost metabolized in vivo because the urinary and biliary excreated amounts of TMB and N-TMB were lower than 0.1% of the administered dose. According to the hepatic biotransformation model and metabolic pathways of TMB proposed, it was found that the fraction of systemic clearance of TMB which formed N-TMB in liver$(G_{mi})$ was 0.826, that of TMB which furnishes the available N-TMB to the systemic circulation$(F_{mi})$ was 0.083, and the absolute hepatic bioavailability of N-TMB formed trom TMB$(F_{mi.p})$ was 0.1. These results showed that TMB was suspected of the sequential hepatic first-pass metabolism and N-demethylated by 82.6%. Therefore, the residue would be hydrolyzed by the esterase in the liver. That is, the ability of N-demethylation of TMB was 4.75-fold larger than that of hydrolysis by the esterase in rats.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.22-25
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• 1998

These studies were conducted to develope analysis method of herbicide quizalofop-ethyl by Gas Liquid Chromatography(GLC) and Enzyme-Linked Immunosoment Assay(ELISA) in soil and plant. Quizalofop produced by hydrolysis of quizalofop-ethyl was conjugated with bovine serum albumin(BSA). Quizalofop antibody was developed in rabbits by using BSA conjugation. Antibody titer, incubation temperature, and incubation time was 32,000, $37^{\circ}C$ and 4hours respectively. Minimum detection limit of quizalofop-ethyl by ELISA was 5ppb. Quizalofop-ethyl recovery from soil by ELISA was more than 95percent. Minimum detection limit of quizalofop-ethyl by GLC was 5ppb. Quizalofop-ethyl recovery from soil by GLC was from 89 percent to 100 percent. Minimun detection limit of quizalofop-ethyl by HPLC was 100ppb. Quizalofop-ethyl recovery from soil by HPLC was 89.6 percent.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.409-416
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• 1992

The optimum cultural temperature and time for the pullulanase production by Bacillus cereus were $15^{\circ}C$ and 72 hrs, respectively. The addition of casein, nutrient broth and egg albumin to the basal medium, respectively, increased greatly the enzyme production. The enzyme was purified by ammonium sulfate fractionation, CM-cellulose and DEAE-cellulose column chromatographies. The specific activity of the purified enzyme was 29.09 U/mg protein and the yield of enzyme activity was 17.1% The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis and its molecular weight was estimated to be 61,000 by SDSpolyacrylamide disc gel electrophoresis. The isoelectric point for the purified enzyme was pH 7.0. The optimum temperature and pH were $40^{\circ}C$ and 6.5. The purified enzyme was stable below $35^{\circ}C$ and in the pH range of 6.5-11.0. It was greatly inhibited by $Ag^{+}$, $Hg^{2+}$ and $Zn^{2+}$, and its thermal stability was increased by the addition of $Ca^{2+}$ Among various substrates, pullulan was favorably hydrolyzed by the purified enzyme and the hydrolysis product 011 pulluIan was maltotriose.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.284-292
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• 2015

We explored preprocessing-mediated quality changes in red snow crab fish sauce. A control (C) group and groups treated with autolysis (A), boiling (B), enzymatic hydrolysis (E), and addition of Aspergillus oryzae (K) were formed. The titratable acidity of the K group increased with storage time, whereas that of groups C, A, B, and E decreased. The total and amino nitrogen contents initially increased on storage of all samples, but decreased in later periods. The total plate count (TPC) of the K group was initially 5.26 log CFU/mL and increased to 7.28 log CFU/mL at 3 months of storage. The TPCs of the C, A, B, and E groups were initially <5.00 log CFU/mL and decreased with storage. The lactic acid bacteria count of the K group was initially 4.80 log CFU/mL and increased until month 5 to approximately 6.06 log CFU/mL. The K group scored higher in terms of sensory attributes than the other groups and maintained marketable scores for all relevant properties (color, flavor, off-odor, and overall acceptance). Furthermore, the free amino acid content of the K group was the highest among all groups at approximately 3,000 mg per 100 g. These results suggest that K treatment may be beneficial in the preparation of fermented fish sauce.

• KSBB Journal
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• v.18 no.6
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• pp.495-499
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• 2003

The effect of operating parameters (reaction temperature and time) and reaction modes (batch and semi-batch) on the behavior of amino acid production from hydrothermal decomposition of fish-derived wastes was investigated. The amino acids obtained in batch experiments at temperature of 250$^{\circ}C$ were mainly alanine (Ala) and glycine (Gly) at maximum yield of 65 and 28mg/g-dry fish, respectively. At relatively lower temperature of 200$^{\circ}C$, the yield of high-molecular-weight amino acids such as aspartic acid (Asp) and serine (Ser) is high, but decreases as temperature increases. It is likely that high-molecular-weight amino acids decompose faster than low-molecular ones. Semi-batch mode of reaction suppressed decomposition of amino acids into organic acids (or volatile materials) by continuously removing the products from the reaction zone as soon as they are formed. Thus, large amount of high-molecular-weight amino acids such as Asp and Ser at this reaction mode was observed.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.2
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• pp.65-72
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• 2015

Objectives To investigate and validate potential standard compounds for standardization of Sinbaro3 pharmacopuncture prepared at OO Hospital of Korean Medicine. Methods Sinbaro3 pharmacopuncture was prepared by extraction, purification and hydrolysis of Harpagophytum procumbens, and various potential standard compounds were quantified through HPLC-UV and HPLC-MS analysis. Validation was examined by assessing specificity, linearity, precision, and accuracy. Results The retention time of harpagide and cinnamic acid were 15.2 min and 28.2 min, respectively, and both showed good linearity in analysis by concentration at 0.9999 and 0.9998, respectively. Intra-day variation of precision was 0.0015~0.0045% and 0.0058~0.1629%, while inter-day variation of precision was 0.0011~0.0243% and 0.0098~0.1629%, and that of accuracy was 99.53~99.89% and 99.50~99.91%, respectively. Conclusions Harpagide and cinnamic acid, which are hydrolyzates of harpagoside within Sinbaro3 pharmacopuncture, were both validated using HPLC-MS and HPLC-UV analysis, and Sinbaro3 pharmacopuncture contained 78.41 ug/ml harpagide, and 2.05 ug/ml cinnamic acid.

• Polymer(Korea)
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• v.27 no.6
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• pp.542-548
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• 2003

Nanoparticles with unsaturated poly(hydroxyalkanoate)s (UPHAs) biosynthesized with Pseudo-monas oleovorans were prepared by spontaneous emulsification solvent diffusion method. The influence of nanoparticle formation was investigated with various experimental parameters such as sonication conditions, sol-vent, surfactant and polymer contents, etc. The physical and chemical properties of UPHAS and its nanoparticles were characterized using $^1$H- and $\^$13/C-nuclear magnetic resonance spectroscopies, attenuated total reflection infrared spectroscopy, differential scanning calorimetry and gel permeation chromatography. The morphology of particles was observed using scanning electron microscope and the size and distribution of nanoparticles were measured with electrophoretic light scattering spectrophotometer. The mean diameter of particles decreased with increasing sonication amplitude and time. The addition of ethanol into UPHAS chloroform solution decreased the particle size presumably due to increased solvent diffusion into water phase. The particle size increased with increased the concentration of UPHAS solution. Under the 2-4％ poly(vinyl alcohol) (PVA) aqueous solution the minimum mean diameter of particles was shown. The higher degree of hydrolysis and degree of polymerization of PVA increased the mean diameter of particles.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.370-374
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• 1995

By exposing the complex enzyme solution to alkaline condition, it was possible to remove the protease activity selectively without inactivation of soybean cell wall degrading activity of the crude enzyme complex produced by Aspergillus niger CF-34. Optimum reaction conditions were as follow. pH was $9.0{\pm}0.1$, temperature was $20^{\circ}C$ and reaction time was 30 min with gentle stirring. Over 90% of protease activity could be eliminated while the activities of pectinase, polygalacturonase, xylanase, carboxymethyl cellulase and soybean cell wall degrading enzyme were maintained to $80{\sim}100%$. Through alkali treatment, it was discovered that the quality and organoleptic properties of soy protein produced by this enzymes were improved because the hydrolysis of protein and formation of bitter peptide were decreased.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.818-825
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• 2012

Keratinases are exciting keratin-degrading enzymes; however, there have been relatively few studies on their immobilization. A keratinolytic protease from Chryseobacterium sp. kr6 was purified and its partial sequence determined using mass spectrometry. No significant homology to other microbial peptides in the NCBI database was observed. Certain parameters for immobilization of the purified keratinase on chitosan beads were investigated. The production of the chitosan beads was optimized using factorial design and surface response techniques. The optimum chitosan bead production for protease immobilization was a 20 g/l chitosan solution in acetic acid [1.5% (v/v)], glutaraldehyde ranging from 34 g to 56 g/l, and an activation time between 6 and 10 h. Under these conditions, above 80% of the enzyme was immobilized on the support. The behavior of the keratinase loading on the chitosan beads surface was well described using the Langmuir model. The maximum capacity of the support ($q_m$) and dissociation constant ($K_d$) were estimated as 58.8 U/g and 0.245 U/ml, respectively. The thermal stability of the immobilized enzyme was also improved around 2-fold, when compared with that of the free enzyme, after 30 min at $65^{\circ}C$. In addition, the activity of the immobilized enzyme remained at 63.4% after it was reused five times. Thus, the immobilized enzyme exhibited an improved thermal stability and remained active after several uses.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.277-288
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• 2017

Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p-Nitrophenyl palmitate (pNPP) hydrolysis was maximal at $40^{\circ}C$ and pH 7.0 for the R. miehei lipase, and at $30^{\circ}C$ and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to pNPP, but the $V_{max}$ of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM $Hg^{2+}$, $Zn^{2+}$, or $Mn^{2+}$, 10 mM N-bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n-hexane, cyclohexane, n-heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the pNPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p-nitrophenyl (pNP) esters with C8-C16 acids, exhibiting maximum activity towards pNP-caprylate (R. miehei) and pNP-dodecanoate (Rh. oryzae). The purified lipases are promising candidates for various biotechnological applications.